Why do cats purr? A purr is one clue about how a cat feels. A cat gives other clues too, with its tail, its ears and its eyes.

Cats purr when they are happy, even while they eat.

A cat can also purr when it is hurt, hungry or nervous. So a purr does not always mean a happy cat.

Look at the tail. A cat with its tail held straight up is usually being friendly. A cat that tucks its tail low or between its legs may feel scared. A puffed-out tail makes a cat look bigger.

Look at the ears. A cat with its ears flat against its head is often afraid or upset. Look at the eyes. Relaxed cats often blink slowly and half close their eyes.

A content cat may knead. It presses its paws on a soft surface, as if it were kneading bread dough. Cats also rub their faces and bodies on things to leave their scent there.

A cat's whiskers are special thick hairs. They help it feel its way around. Whiskers also help a cat tell whether it can squeeze through a narrow space.

Cats have a strong sense of smell. They hear very high sounds that people cannot hear. Many cats are most active at dawn and dusk.

Kittens finish drinking their mother's milk by about 8 weeks old. They learn to hunt by copying their mother.

Kittens may purr when they drink their mother's milk. A mother cat purrs to her kittens, which is thought to help them feel calm.

Words to know

• purr: soft cat hum
• whiskers: cat face hairs
• knead: press with paws
• scent: smell
• dusk: early evening